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Class org.netlib.lapack.DPTTRF

java.lang.Object
   |
   +----org.netlib.lapack.DPTTRF

public class DPTTRF

extends Object

DPTTRF is a simplified interface to the JLAPACK routine dpttrf.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines.  Using this interface also allows you
to omit offset and leading dimension arguments.  However, because
of these conversions, these routines will be slower than the low
level ones.  Following is the description from the original Fortran
source.  Contact seymour@cs.utk.edu with any questions.

 *     ..
 *
 *  Purpose
 *  =======
 *
 *  DPTTRF computes the factorization of a real symmetric positive
 *  definite tridiagonal matrix A.
 *
 *  If the subdiagonal elements of A are supplied in the array E, the
 *  factorization has the form A = L*D*L**T, where D is diagonal and L
 *  is unit lower bidiagonal; if the superdiagonal elements of A are
 *  supplied, it has the form A = U**T*D*U, where U is unit upper
 *  bidiagonal.  (The two forms are equivalent if A is real.)
 *
 *  Arguments
 *  =========
 *
 *  N       (input) INTEGER
 *          The order of the matrix A.  N >= 0.
 *
 *  D       (input/output) DOUBLE PRECISION array, dimension (N)
 *          On entry, the n diagonal elements of the tridiagonal matrix
 *          A.  On exit, the n diagonal elements of the diagonal matrix
 *          D from the L*D*L**T factorization of A.
 *
 *  E       (input/output) DOUBLE PRECISION array, dimension (N-1)
 *          On entry, the (n-1) off-diagonal elements of the tridiagonal
 *          matrix A.
 *          On exit, the (n-1) off-diagonal elements of the unit
 *          bidiagonal factor L or U from the factorization of A.
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *          > 0:  if INFO = i, the leading minor of order i is not
 *                positive definite; if i < N, the factorization could
 *                not be completed, while if i = N, the factorization was
 *                completed, but D(N) = 0.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

DPTTRF()

DPTTRF(int, double[], double[], intW)

 public DPTTRF()

 public static void DPTTRF(int n,
                           double d[],
                           double e[],
                           intW info)

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